1. Technical Field
The present invention relates to a liquid storage container and a liquid filling method and a liquid refilling method using the same that are suitable in a case where liquid allowing dispersoid formed of particles, such as a pigment, to easily sediment in a dispersion medium, such as a solvent, is used.
2. Related Art
Ink jet printers have been widely used as liquid ejecting apparatuses that eject liquid onto a target. More specifically, the ink jet printer includes a carriage, a recording head mounted on the carriage, and an ink container that stores ink as liquid. Printing is performed on a recording medium by supplying ink from an ink pack of the ink container to the recording head and discharging (ejecting) ink from a nozzle of the recording head while making the carriage relatively move with respect to the recording medium.
As printing is diversified in recent years, pigment dispersed ink or ink in which various kinds of powder are dispersed in a solvent (hereinafter, referred to as ‘pigment ink’) is increasingly used. This pigment ink uses a pigment as a coloring matter and is obtained by dispersing the pigment in an ink solvent (dispersion medium). If the pigment ink is left alone for a long period of time, a problem that the pigment sediments in the solvent occurs because the pigment itself is dispersed as particles in the ink solvent, even though a printed matter using the pigment ink has excellent light-resistant property and water-resistant property.
For this reason, in the case where the idle period of a printer is relatively long or a new ink cartridge is used, concentration unevenness that the pigment concentration is low at an upper side of an ink pack and is high at a lower side of the ink pack due to sedimentation of the pigment occurs. As a result, a problem that concentration unevenness occurs in printing arises. In an extreme case, a condensed pigment clogs a filter member extending up to a recording head or enters into a complicated ink passage formed in the recording head to clog the portion. This may eventually cause ink droplets not to be discharged from the recording head.
For example, JP-A-2002-192742 (refer to FIGS. 4 to 7) discloses that in a printer and an ink cartridge using pigment ink, for example, vibration generated by a piezoelectric element is transmitted to the ink cartridge so that ink stored in the ink cartridge can be vibrated to be stirred.
JP-A-2005-66520 (refer to FIG. 2) discloses that concentration unevenness of ink within an ink pack is prevented by extending an operated portion of a stirring body, which is rocked by a driving portion, to the end of the ink pack located opposite a side where a liquid lead-out member protrudes from the ink pack.
In addition, examples in which various kinds of members are disposed within a liquid containing body are disclosed in JP-A-1-208145 (refer to FIGS. 2 and 3) and JP-A-2006-69129 (refer to FIGS. 12 and 13). JP-A-1-208145 discloses that vacuum portions enclosed by a partition wall member, which is insoluble in an ink composition and has gas permeability, are disposed even in an ink pack. Here, dissolved gas is diffused to the vacuum portion by partial pressure such that the concentration of nitrogen or oxygen dissolved in ink is decreased, thereby reducing a temporal change of ink. However, prevention of the concentration unevenness is not disclosed in JP-A-1-208145. JP-A-2006-69129 disposes that a movable stirring body that sediments and a floating body that floats are disposed in an ink containing chamber of an on-carriage type ink cartridge. Ink is stirred by moving the movable stirring body with the movement of a carriage, and generation of abnormal noises caused by collision of the movable stirring body with an inner wall of the ink containing chamber at the time of a decrease in the amount of remaining ink is reduced.
In the case of the technique disclosed in JP-A-2002-192742, there was a problem that the vibration effect was not sufficient since the vibration was given from the outside of ink. For example, there was a case in which vibration was absorbed in a member of a tank to become weak or was transmitted only to the neighborhood of a wall surface of a tank and accordingly, sufficient stirring could not be expected. In addition, when vibration was generated, it was difficult to sufficiently stir the whole ink even if the neighborhood of a place where the vibration was generated was stirred.
An ink pack deforms as ink is taken out and changes to the volume according to the amount of remaining ink. In the technique of stirring ink in the liquid containing body as disclosed in JP-A-2005-66520, the amount of displacement of the stirring body is decreased when the amount of remaining ink is reduced due to obstruction of the inner wall of the ink pack. Therefore, the ink stirring effect particularly when the amount of remaining ink is reduced is small.
The technique disclosed in JP-A-2006-69129 can be applied only to the on-carriage type ink cartridge but cannot be applied to an off-carriage type ink cartridge.